1. Field of the Invention
The present invention relates to an electronic musical apparatus having a function of playing music data including performance data on a plurality of tracks.
2. Description of the Related Art
An electronic musical instrument such as a keyboard or the like has conventionally been known which has a function of playing music data including performance data on a plurality of tracks. Further, in the electronic musical instrument having such a function, when a user presses a practice switch (lesson button), the instrument plays performance data on tracks relating to parts other than the part designated as a lesson part, while the instrument, for the track relating to the lesson part, instead of playing its performance data, instructs a key to be hit on a keyboard by turning on its lamp or the like or displays contents to be played as a score based on the performance data.
Such electronic musical instruments are described, for example, in user's manual of “PORTATONE EZ-J53 (trade name)” available from YAMAHA CORPORATION, pp. 35 to 44 and in Japanese Publication of Patent Application No. 2003-223165 (JP 2003-223165, A).
Besides, for music data for use in a keyboard musical instrument such as an automatic piano, performance data for right hand (for melody) and performance data for left hand (for accompaniment) are separately stored so that these data are accessible separately, thereby allowing test-listen of only the right-hand or left-hand performance part prior to performance lesson. Such technology is described in JP Japanese Publication of Patent Application No. 6-118867 (JP 6-118867, A).